Conventions of Composition Rule 148

Rules: To express subjective relation to a gerund, use the possessive case. To express measure, use the possessive case. (For how to form singular and plural possessives, see rule 106.)

Examples:

Correct (singular): What is the importance of the navy’s being prepared for war?

Correct (plural): They disapprove of their sons’ playing football.

Correct (singular): A dollar’s worth, a moment’s notice, an hour’s delay, a month’s salary.

Correct (plural): Ten dollars’ worth, three days’ notice, four hours’ delay.

Practice creating special possessives:

1. Watching Michael Phelps swimming brings joy to millions.
2. Casey wondered if his husband knew about his plan for them going on a trip to Alaska.
3. We still had three days drive to get to Graceland.

Resources for further explanation of special possessive cases:

The English Space's Using Possessive 's with Time Phrases

Grammar Tips' Possessives Precede Gerunds